/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef MP3_DEMUXER_H_
#define MP3_DEMUXER_H_
#include "MediaDataDemuxer.h"
#include "MediaResource.h"
#include "MP3FrameParser.h"
namespace mozilla {
class MP3TrackDemuxer;
DDLoggedTypeDeclNameAndBase(MP3Demuxer, MediaDataDemuxer);
DDLoggedTypeNameAndBase(MP3TrackDemuxer, MediaTrackDemuxer);
class MP3Demuxer :
public MediaDataDemuxer,
public DecoderDoctorLifeLogger<MP3Demuxer> {
public:
// MediaDataDemuxer interface.
explicit MP3Demuxer(MediaResource* aSource);
RefPtr<InitPromise> Init() override;
uint32_t GetNumberTracks(TrackInfo::TrackType aType)
const override;
already_AddRefed<MediaTrackDemuxer> GetTrackDemuxer(
TrackInfo::TrackType aType, uint32_t aTrackNumber) override;
bool IsSeekable()
const override;
void NotifyDataArrived() override;
void NotifyDataRemoved() override;
private:
// Synchronous initialization.
bool InitInternal();
RefPtr<MediaResource> mSource;
RefPtr<MP3TrackDemuxer> mTrackDemuxer;
};
// The MP3 demuxer used to extract MPEG frames and side information out of
// MPEG streams.
class MP3TrackDemuxer :
public MediaTrackDemuxer,
public DecoderDoctorLifeLogger<MP3TrackDemuxer> {
public:
// Constructor, expecting a valid media resource.
explicit MP3TrackDemuxer(MediaResource* aSource);
// Initializes the track demuxer by reading the first frame for meta data.
// Returns initialization success state.
bool Init();
// Returns the total stream length if known, -1 otherwise.
int64_t StreamLength()
const;
// Returns the estimated stream duration, or a 0-duration if unknown.
media::NullableTimeUnit Duration()
const;
// Returns the estimated duration up to the given frame number,
// or a 0-duration if unknown.
media::TimeUnit Duration(int64_t aNumFrames)
const;
// Returns the estimated current seek position time.
media::TimeUnit SeekPosition()
const;
const FrameParser::Frame& LastFrame()
const;
RefPtr<MediaRawData> DemuxSample();
const ID3Parser::ID3Header& ID3Header()
const;
const FrameParser::VBRHeader& VBRInfo()
const;
// MediaTrackDemuxer interface.
UniquePtr<TrackInfo> GetInfo()
const override;
RefPtr<SeekPromise> Seek(
const media::TimeUnit& aTime) override;
RefPtr<SamplesPromise> GetSamples(int32_t aNumSamples = 1) override;
void Reset() override;
RefPtr<SkipAccessPointPromise> SkipToNextRandomAccessPoint(
const media::TimeUnit& aTimeThreshold) override;
int64_t GetResourceOffset()
const override;
media::TimeIntervals GetBuffered() override;
// Return the duration in frames of the encoder delay.
uint32_t EncoderDelayFrames()
const;
// Return the duration in frames of the padding.
uint32_t PaddingFrames()
const;
private:
// Destructor.
~MP3TrackDemuxer() =
default;
// Fast approximate seeking to given time.
media::TimeUnit FastSeek(
const media::TimeUnit& aTime);
// Seeks by scanning the stream up to the given time for more accurate
// results.
media::TimeUnit ScanUntil(
const media::TimeUnit& aTime);
// Finds the first valid frame and returns its byte range if found
// or a null-byte range otherwise.
MediaByteRange FindFirstFrame();
// Finds the next valid frame and returns its byte range if found
// or a null-byte range otherwise.
MediaByteRange FindNextFrame();
// Skips the next frame given the provided byte range.
bool SkipNextFrame(
const MediaByteRange& aRange);
// Returns the next MPEG frame, if available.
already_AddRefed<MediaRawData> GetNextFrame(
const MediaByteRange& aRange);
// Updates post-read meta data.
void UpdateState(
const MediaByteRange& aRange);
// Returns the estimated offset for the given frame index.
int64_t OffsetFromFrameIndex(int64_t aFrameIndex)
const;
// Returns the estimated frame index for the given offset.
int64_t FrameIndexFromOffset(int64_t aOffset)
const;
// Returns the estimated frame index for the given time.
int64_t FrameIndexFromTime(
const media::TimeUnit& aTime)
const;
// Reads aSize bytes into aBuffer from the source starting at aOffset.
// Returns the actual size read.
uint32_t Read(uint8_t* aBuffer, int64_t aOffset, uint32_t aSize);
// Returns the average frame length derived from the previously parsed frames.
double AverageFrameLength()
const;
// Returns the number of frames reported by the header if it's valid. Nothing
// otherwise.
Maybe<uint32_t> ValidNumAudioFrames()
const;
// Return the duration of the encoder delay.
media::TimeUnit EncoderDelay()
const;
// Return the duration of the padding.
media::TimeUnit Padding()
const;
// The (hopefully) MPEG resource.
MediaResourceIndex mSource;
// MPEG frame parser used to detect frames and extract side info.
FrameParser mParser;
// Whether we've locked onto a valid sequence of frames or not.
bool mFrameLock;
// Current byte offset in the source stream.
int64_t mOffset;
// Byte offset of the begin of the first frame, or 0 if none parsed yet.
int64_t mFirstFrameOffset;
// Total parsed frames.
uint64_t mNumParsedFrames;
// Current frame index.
int64_t mFrameIndex;
// Sum of parsed frames' lengths in bytes.
int64_t mTotalFrameLen;
// Samples per frame metric derived from frame headers or 0 if none available.
uint32_t mSamplesPerFrame;
// Samples per second metric derived from frame headers or 0 if none
// available.
uint32_t mSamplesPerSecond;
// Channel count derived from frame headers or 0 if none available.
uint32_t mChannels;
// Audio track config info.
UniquePtr<AudioInfo> mInfo;
// Number of frames to skip at the beginning
uint32_t mEncoderDelay = 0;
// Number of frames to skip at the end
uint32_t mEncoderPadding = 0;
int32_t mRemainingEncoderPadding = 0;
// End of stream has been found
bool mEOS =
false;
};
}
// namespace mozilla
#endif
